A judge has previously described the couple as “two perfectly decent people [who] have ended up in custody because of the love of their child".

But Letts said in an online statement he "hated" his parents "for the sake of Allaah" because they are non-believers, and called on them to convert.

He added: "They reject the religion of truth, so I reject them. I hate the Kuffaar [non-believers], and am free from them. Die in your rage."

Letts told Channel 4: "I came here searching for the truth, and people of the truth, and I don't regret that I came.

"I searched for the people of truth, and I found a lot of them here. I found people that act on what they learn and teach, and benefited a lot from them, Alhamdulillah (praise be to God)."

When asked if he is an Islamic State fighter, he said: "Currently I'm not," and added: "I'm not and nor do I agree with lot of what they follow."

In a separate online statement in Arabic, which he said should be remembered as his final words if he is killed, he wrote: "I oppose so-called Islamic State, but that doesn't mean I am with you, the dirty non-Muslims."

Asked if he is a terrorist, he said: "Do you mean by the English Government's definition, that anyone that opposes a non-Islamic system and man-made laws, then, of course, by that definition, I suppose they'd say I'm a terrorist..."

He said he does not think he would be welcome if he returned to Britain, but that he misses the "small things" - specifically Krispy Kreme doughnuts and kebabs.

Despite a near-miss when he said he narrowly survived an air strike with just a "scratch", the Briton said he is not afraid of death: "I'm not worried. Everyone is going to die on their day. Whether it's by a drone strike. A Muslim understands that his life is between the hands of Allaah.